DESCRIPTION (Verbatim from the Applicant's Abstract): The bioartificial liver has been proposed to perform liver function during hepatic failure unit the native liver has regenerated, or until transplantation is possible. The ideal bioartificial liver would mimic normal liver function. A bioartificial liver could also be used to periodically detoxify those patients with chronic liver diseases. In this hybrid liver system, patients' blood is circulated through a replaceable cartridge interfaced with constantly recirculating viable liver cells, removing toxins from the blood. This proposal will focus on meeting the oxygen demands of the hepatocyte in the recirculating loop. We propose to develop a perfluorinated membrane that will provide bubble less oxygenation, with the required transport characteristics to maintain hepatocyte viability. Additionally, the membrane would offer enhanced resistance to "wet out," and other fouling phenomena associated with conventional hydrophobic membranes, and thus extend the lifetime of liver cells, and reduce the likelihood of introducing pathogenic organisms into the media. Successful completion of the proposed R&D effort will produce and enhanced system that can provide longer-term liver support. PROPOSED COMMERCIAL APPLICATION: Bioartificial livers that provide long term hepatocyte function are expected to provide supportive care and a bridge to transplantation for patients with chronic liver diseases, and improve the prognosis of patients with acute liver failure, avoiding altogether the need for transplantation. A recirculating interfacing device could potentially be used to test the safety of new drugs. Our membrane technology will substantially improve oxygen transfer within the bioartificial liver, and significantly improve its performance.